package ssh

import (
	"io"
	"io/ioutil"
	"net"
	"path"
	"sync"

	gossh "golang.org/x/crypto/ssh"
)

const (
	agentRequestType = "auth-agent-req@openssh.com"
	agentChannelType = "auth-agent@openssh.com"

	agentTempDir    = "auth-agent"
	agentListenFile = "listener.sock"
)

// contextKeyAgentRequest is an internal context key for storing if the
// client requested agent forwarding
// client requested agent forwarding
var contextKeyAgentRequest = &contextKey{"auth-agent-req"}

// SetAgentRequested sets up the session context so that AgentRequested
// returns true.
func SetAgentRequested(ctx Context) {
	ctx.SetValue(contextKeyAgentRequest, true)
}

// AgentRequested returns true if the client requested agent forwarding.
func AgentRequested(sess Session) bool {
	return sess.Context().Value(contextKeyAgentRequest) == true
}

// NewAgentListener sets up a temporary Unix socket that can be communicated
// to the session environment and used for forwarding connections.
func NewAgentListener() (net.Listener, error) {
	dir, err := ioutil.TempDir("", agentTempDir)
	if err != nil {
		return nil, err
	}
	l, err := net.Listen("unix", path.Join(dir, agentListenFile))
	if err != nil {
		return nil, err
	}
	return l, nil
}

// ForwardAgentConnections takes connections from a listener to proxy into the
// session on the OpenSSH channel for agent connections. It blocks and services
// connections until the listener stop accepting.
func ForwardAgentConnections(l net.Listener, s Session) {
	sshConn := s.Context().Value(ContextKeyConn).(gossh.Conn)
	for {
		conn, err := l.Accept()
		if err != nil {
			return
		}
		go func(conn net.Conn) {
			defer conn.Close()
			channel, reqs, err := sshConn.OpenChannel(agentChannelType, nil)
			if err != nil {
				return
			}
			defer channel.Close()
			go gossh.DiscardRequests(reqs)
			var wg sync.WaitGroup
			wg.Add(2)
			go func() {
				io.Copy(conn, channel)
				conn.(*net.UnixConn).CloseWrite()
				wg.Done()
			}()
			go func() {
				io.Copy(channel, conn)
				channel.CloseWrite()
				wg.Done()
			}()
			wg.Wait()
		}(conn)
	}
}
/*
 *
 * Copyright 2014 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

 package grpc

 import (
	 "context"
 )
 
 // Invoke sends the RPC request on the wire and returns after response is
 // received.  This is typically called by generated code.
 //
 // All errors returned by Invoke are compatible with the status package.
 func (cc *ClientConn) Invoke(ctx context.Context, method string, args, reply interface{}, opts ...CallOption) error {
	 // allow interceptor to see all applicable call options, which means those
	 // configured as defaults from dial option as well as per-call options
	 opts = combine(cc.dopts.callOptions, opts)
 
	 if cc.dopts.unaryInt != nil {
		 return cc.dopts.unaryInt(ctx, method, args, reply, cc, invoke, opts...)
	 }
	 return invoke(ctx, method, args, reply, cc, opts...)
 }
 
 func combine(o1 []CallOption, o2 []CallOption) []CallOption {
	 // we don't use append because o1 could have extra capacity whose
	 // elements would be overwritten, which could cause inadvertent
	 // sharing (and race conditions) between concurrent calls
	 if len(o1) == 0 {
		 return o2
	 } else if len(o2) == 0 {
		 return o1
	 }
	 ret := make([]CallOption, len(o1)+len(o2))
	 copy(ret, o1)
	 copy(ret[len(o1):], o2)
	 return ret
 }
 
 // Invoke sends the RPC request on the wire and returns after response is
 // received.  This is typically called by generated code.
 //
 // DEPRECATED: Use ClientConn.Invoke instead.
 func Invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) error {
	 return cc.Invoke(ctx, method, args, reply, opts...)
 }
 
 var unaryStreamDesc = &StreamDesc{ServerStreams: false, ClientStreams: false}
 
 func invoke(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, opts ...CallOption) error {
	 cs, err := newClientStream(ctx, unaryStreamDesc, cc, method, opts...)
	 if err != nil {
		 return err
	 }
	 if err := cs.SendMsg(req); err != nil {
		 return err
	 }
	 return cs.RecvMsg(reply)
 }
 /*
 *
 * Copyright 2014 gRPC authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package grpc

import (
	"context"
	"fmt"
	"io"
	"math"
	"net"
	"strconv"
	"strings"
	"sync"
	"testing"
	"time"

	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/internal/transport"
	"google.golang.org/grpc/status"
)

var (
	expectedRequest  = "ping"
	expectedResponse = "pong"
	weirdError       = "format verbs: %v%s"
	sizeLargeErr     = 1024 * 1024
	canceled         = 0
)

type testCodec struct {
}

func (testCodec) Marshal(v interface{}) ([]byte, error) {
	return []byte(*(v.(*string))), nil
}

func (testCodec) Unmarshal(data []byte, v interface{}) error {
	*(v.(*string)) = string(data)
	return nil
}

func (testCodec) String() string {
	return "test"
}

type testStreamHandler struct {
	port string
	t    transport.ServerTransport
}

func (h *testStreamHandler) handleStream(t *testing.T, s *transport.Stream) {
	p := &parser{r: s}
	for {
		pf, req, err := p.recvMsg(math.MaxInt32)
		if err == io.EOF {
			break
		}
		if err != nil {
			return
		}
		if pf != compressionNone {
			t.Errorf("Received the mistaken message format %d, want %d", pf, compressionNone)
			return
		}
		var v string
		codec := testCodec{}
		if err := codec.Unmarshal(req, &v); err != nil {
			t.Errorf("Failed to unmarshal the received message: %v", err)
			return
		}
		if v == "weird error" {
			h.t.WriteStatus(s, status.New(codes.Internal, weirdError))
			return
		}
		if v == "canceled" {
			canceled++
			h.t.WriteStatus(s, status.New(codes.Internal, ""))
			return
		}
		if v == "port" {
			h.t.WriteStatus(s, status.New(codes.Internal, h.port))
			return
		}

		if v != expectedRequest {
			h.t.WriteStatus(s, status.New(codes.Internal, strings.Repeat("A", sizeLargeErr)))
			return
		}
	}
	// send a response back to end the stream.
	data, err := encode(testCodec{}, &expectedResponse)
	if err != nil {
		t.Errorf("Failed to encode the response: %v", err)
		return
	}
	hdr, payload := msgHeader(data, nil)
	h.t.Write(s, hdr, payload, &transport.Options{})
	h.t.WriteStatus(s, status.New(codes.OK, ""))
}

type server struct {
	lis        net.Listener
	port       string
	addr       string
	startedErr chan error // sent nil or an error after server starts
	mu         sync.Mutex
	conns      map[transport.ServerTransport]bool
}

type ctxKey string

func newTestServer() *server {
	return &server{startedErr: make(chan error, 1)}
}

// start starts server. Other goroutines should block on s.startedErr for further operations.
func (s *server) start(t *testing.T, port int, maxStreams uint32) {
	var err error
	if port == 0 {
		s.lis, err = net.Listen("tcp", "localhost:0")
	} else {
		s.lis, err = net.Listen("tcp", "localhost:"+strconv.Itoa(port))
	}
	if err != nil {
		s.startedErr <- fmt.Errorf("failed to listen: %v", err)
		return
	}
	s.addr = s.lis.Addr().String()
	_, p, err := net.SplitHostPort(s.addr)
	if err != nil {
		s.startedErr <- fmt.Errorf("failed to parse listener address: %v", err)
		return
	}
	s.port = p
	s.conns = make(map[transport.ServerTransport]bool)
	s.startedErr <- nil
	for {
		conn, err := s.lis.Accept()
		if err != nil {
			return
		}
		config := &transport.ServerConfig{
			MaxStreams: maxStreams,
		}
		st, err := transport.NewServerTransport("http2", conn, config)
		if err != nil {
			continue
		}
		s.mu.Lock()
		if s.conns == nil {
			s.mu.Unlock()
			st.Close()
			return
		}
		s.conns[st] = true
		s.mu.Unlock()
		h := &testStreamHandler{
			port: s.port,
			t:    st,
		}
		go st.HandleStreams(func(s *transport.Stream) {
			go h.handleStream(t, s)
		}, func(ctx context.Context, method string) context.Context {
			return ctx
		})
	}
}

func (s *server) wait(t *testing.T, timeout time.Duration) {
	select {
	case err := <-s.startedErr:
		if err != nil {
			t.Fatal(err)
		}
	case <-time.After(timeout):
		t.Fatalf("Timed out after %v waiting for server to be ready", timeout)
	}
}

func (s *server) stop() {
	s.lis.Close()
	s.mu.Lock()
	for c := range s.conns {
		c.Close()
	}
	s.conns = nil
	s.mu.Unlock()
}

func setUp(t *testing.T, port int, maxStreams uint32) (*server, *ClientConn) {
	return setUpWithOptions(t, port, maxStreams)
}

func setUpWithOptions(t *testing.T, port int, maxStreams uint32, dopts ...DialOption) (*server, *ClientConn) {
	server := newTestServer()
	go server.start(t, port, maxStreams)
	server.wait(t, 2*time.Second)
	addr := "localhost:" + server.port
	dopts = append(dopts, WithBlock(), WithInsecure(), WithCodec(testCodec{}))
	cc, err := Dial(addr, dopts...)
	if err != nil {
		t.Fatalf("Failed to create ClientConn: %v", err)
	}
	return server, cc
}

func (s) TestUnaryClientInterceptor(t *testing.T) {
	parentKey := ctxKey("parentKey")

	interceptor := func(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, invoker UnaryInvoker, opts ...CallOption) error {
		if ctx.Value(parentKey) == nil {
			t.Fatalf("interceptor should have %v in context", parentKey)
		}
		return invoker(ctx, method, req, reply, cc, opts...)
	}

	server, cc := setUpWithOptions(t, 0, math.MaxUint32, WithUnaryInterceptor(interceptor))
	defer func() {
		cc.Close()
		server.stop()
	}()

	var reply string
	ctx := context.Background()
	parentCtx := context.WithValue(ctx, ctxKey("parentKey"), 0)
	if err := cc.Invoke(parentCtx, "/foo/bar", &expectedRequest, &reply); err != nil || reply != expectedResponse {
		t.Fatalf("grpc.Invoke(_, _, _, _, _) = %v, want <nil>", err)
	}
}

func (s) TestChainUnaryClientInterceptor(t *testing.T) {
	var (
		parentKey    = ctxKey("parentKey")
		firstIntKey  = ctxKey("firstIntKey")
		secondIntKey = ctxKey("secondIntKey")
	)

	firstInt := func(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, invoker UnaryInvoker, opts ...CallOption) error {
		if ctx.Value(parentKey) == nil {
			t.Fatalf("first interceptor should have %v in context", parentKey)
		}
		if ctx.Value(firstIntKey) != nil {
			t.Fatalf("first interceptor should not have %v in context", firstIntKey)
		}
		if ctx.Value(secondIntKey) != nil {
			t.Fatalf("first interceptor should not have %v in context", secondIntKey)
		}
		firstCtx := context.WithValue(ctx, firstIntKey, 1)
		err := invoker(firstCtx, method, req, reply, cc, opts...)
		*(reply.(*string)) += "1"
		return err
	}

	secondInt := func(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, invoker UnaryInvoker, opts ...CallOption) error {
		if ctx.Value(parentKey) == nil {
			t.Fatalf("second interceptor should have %v in context", parentKey)
		}
		if ctx.Value(firstIntKey) == nil {
			t.Fatalf("second interceptor should have %v in context", firstIntKey)
		}
		if ctx.Value(secondIntKey) != nil {
			t.Fatalf("second interceptor should not have %v in context", secondIntKey)
		}
		secondCtx := context.WithValue(ctx, secondIntKey, 2)
		err := invoker(secondCtx, method, req, reply, cc, opts...)
		*(reply.(*string)) += "2"
		return err
	}

	lastInt := func(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, invoker UnaryInvoker, opts ...CallOption) error {
		if ctx.Value(parentKey) == nil {
			t.Fatalf("last interceptor should have %v in context", parentKey)
		}
		if ctx.Value(firstIntKey) == nil {
			t.Fatalf("last interceptor should have %v in context", firstIntKey)
		}
		if ctx.Value(secondIntKey) == nil {
			t.Fatalf("last interceptor should have %v in context", secondIntKey)
		}
		err := invoker(ctx, method, req, reply, cc, opts...)
		*(reply.(*string)) += "3"
		return err
	}

	server, cc := setUpWithOptions(t, 0, math.MaxUint32, WithChainUnaryInterceptor(firstInt, secondInt, lastInt))
	defer func() {
		cc.Close()
		server.stop()
	}()

	var reply string
	ctx := context.Background()
	parentCtx := context.WithValue(ctx, ctxKey("parentKey"), 0)
	if err := cc.Invoke(parentCtx, "/foo/bar", &expectedRequest, &reply); err != nil || reply != expectedResponse+"321" {
		t.Fatalf("grpc.Invoke(_, _, _, _, _) = %v, want <nil>", err)
	}
}

func (s) TestChainOnBaseUnaryClientInterceptor(t *testing.T) {
	var (
		parentKey  = ctxKey("parentKey")
		baseIntKey = ctxKey("baseIntKey")
	)

	baseInt := func(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, invoker UnaryInvoker, opts ...CallOption) error {
		if ctx.Value(parentKey) == nil {
			t.Fatalf("base interceptor should have %v in context", parentKey)
		}
		if ctx.Value(baseIntKey) != nil {
			t.Fatalf("base interceptor should not have %v in context", baseIntKey)
		}
		baseCtx := context.WithValue(ctx, baseIntKey, 1)
		return invoker(baseCtx, method, req, reply, cc, opts...)
	}

	chainInt := func(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, invoker UnaryInvoker, opts ...CallOption) error {
		if ctx.Value(parentKey) == nil {
			t.Fatalf("chain interceptor should have %v in context", parentKey)
		}
		if ctx.Value(baseIntKey) == nil {
			t.Fatalf("chain interceptor should have %v in context", baseIntKey)
		}
		return invoker(ctx, method, req, reply, cc, opts...)
	}

	server, cc := setUpWithOptions(t, 0, math.MaxUint32, WithUnaryInterceptor(baseInt), WithChainUnaryInterceptor(chainInt))
	defer func() {
		cc.Close()
		server.stop()
	}()

	var reply string
	ctx := context.Background()
	parentCtx := context.WithValue(ctx, ctxKey("parentKey"), 0)
	if err := cc.Invoke(parentCtx, "/foo/bar", &expectedRequest, &reply); err != nil || reply != expectedResponse {
		t.Fatalf("grpc.Invoke(_, _, _, _, _) = %v, want <nil>", err)
	}
}

func (s) TestChainStreamClientInterceptor(t *testing.T) {
	var (
		parentKey    = ctxKey("parentKey")
		firstIntKey  = ctxKey("firstIntKey")
		secondIntKey = ctxKey("secondIntKey")
	)

	firstInt := func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, streamer Streamer, opts ...CallOption) (ClientStream, error) {
		if ctx.Value(parentKey) == nil {
			t.Fatalf("first interceptor should have %v in context", parentKey)
		}
		if ctx.Value(firstIntKey) != nil {
			t.Fatalf("first interceptor should not have %v in context", firstIntKey)
		}
		if ctx.Value(secondIntKey) != nil {
			t.Fatalf("first interceptor should not have %v in context", secondIntKey)
		}
		firstCtx := context.WithValue(ctx, firstIntKey, 1)
		return streamer(firstCtx, desc, cc, method, opts...)
	}

	secondInt := func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, streamer Streamer, opts ...CallOption) (ClientStream, error) {
		if ctx.Value(parentKey) == nil {
			t.Fatalf("second interceptor should have %v in context", parentKey)
		}
		if ctx.Value(firstIntKey) == nil {
			t.Fatalf("second interceptor should have %v in context", firstIntKey)
		}
		if ctx.Value(secondIntKey) != nil {
			t.Fatalf("second interceptor should not have %v in context", secondIntKey)
		}
		secondCtx := context.WithValue(ctx, secondIntKey, 2)
		return streamer(secondCtx, desc, cc, method, opts...)
	}

	lastInt := func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, streamer Streamer, opts ...CallOption) (ClientStream, error) {
		if ctx.Value(parentKey) == nil {
			t.Fatalf("last interceptor should have %v in context", parentKey)
		}
		if ctx.Value(firstIntKey) == nil {
			t.Fatalf("last interceptor should have %v in context", firstIntKey)
		}
		if ctx.Value(secondIntKey) == nil {
			t.Fatalf("last interceptor should have %v in context", secondIntKey)
		}
		return streamer(ctx, desc, cc, method, opts...)
	}

	server, cc := setUpWithOptions(t, 0, math.MaxUint32, WithChainStreamInterceptor(firstInt, secondInt, lastInt))
	defer func() {
		cc.Close()
		server.stop()
	}()

	ctx := context.Background()
	parentCtx := context.WithValue(ctx, ctxKey("parentKey"), 0)
	_, err := cc.NewStream(parentCtx, &StreamDesc{}, "/foo/bar")
	if err != nil {
		t.Fatalf("grpc.NewStream(_, _, _) = %v, want <nil>", err)
	}
}

func (s) TestInvoke(t *testing.T) {
	server, cc := setUp(t, 0, math.MaxUint32)
	var reply string
	if err := cc.Invoke(context.Background(), "/foo/bar", &expectedRequest, &reply); err != nil || reply != expectedResponse {
		t.Fatalf("grpc.Invoke(_, _, _, _, _) = %v, want <nil>", err)
	}
	cc.Close()
	server.stop()
}

func (s) TestInvokeLargeErr(t *testing.T) {
	server, cc := setUp(t, 0, math.MaxUint32)
	var reply string
	req := "hello"
	err := cc.Invoke(context.Background(), "/foo/bar", &req, &reply)
	if _, ok := status.FromError(err); !ok {
		t.Fatalf("grpc.Invoke(_, _, _, _, _) receives non rpc error.")
	}
	if status.Code(err) != codes.Internal || len(errorDesc(err)) != sizeLargeErr {
		t.Fatalf("grpc.Invoke(_, _, _, _, _) = %v, want an error of code %d and desc size %d", err, codes.Internal, sizeLargeErr)
	}
	cc.Close()
	server.stop()
}

// TestInvokeErrorSpecialChars checks that error messages don't get mangled.
func (s) TestInvokeErrorSpecialChars(t *testing.T) {
	server, cc := setUp(t, 0, math.MaxUint32)
	var reply string
	req := "weird error"
	err := cc.Invoke(context.Background(), "/foo/bar", &req, &reply)
	if _, ok := status.FromError(err); !ok {
		t.Fatalf("grpc.Invoke(_, _, _, _, _) receives non rpc error.")
	}
	if got, want := errorDesc(err), weirdError; got != want {
		t.Fatalf("grpc.Invoke(_, _, _, _, _) error = %q, want %q", got, want)
	}
	cc.Close()
	server.stop()
}

// TestInvokeCancel checks that an Invoke with a canceled context is not sent.
func (s) TestInvokeCancel(t *testing.T) {
	server, cc := setUp(t, 0, math.MaxUint32)
	var reply string
	req := "canceled"
	for i := 0; i < 100; i++ {
		ctx, cancel := context.WithCancel(context.Background())
		cancel()
		cc.Invoke(ctx, "/foo/bar", &req, &reply)
	}
	if canceled != 0 {
		t.Fatalf("received %d of 100 canceled requests", canceled)
	}
	cc.Close()
	server.stop()
}

// TestInvokeCancelClosedNonFail checks that a canceled non-failfast RPC
// on a closed client will terminate.
func (s) TestInvokeCancelClosedNonFailFast(t *testing.T) {
	server, cc := setUp(t, 0, math.MaxUint32)
	var reply string
	cc.Close()
	req := "hello"
	ctx, cancel := context.WithCancel(context.Background())
	cancel()
	if err := cc.Invoke(ctx, "/foo/bar", &req, &reply, WaitForReady(true)); err == nil {
		t.Fatalf("canceled invoke on closed connection should fail")
	}
	server.stop()
}
// Copyright (c) 2012-2018 Ugorji Nwoke. All rights reserved.
// Use of this source code is governed by a MIT license found in the LICENSE file.

// codecgen generates static implementations of the encoder and decoder functions
// for a given type, bypassing reflection, and giving some performance benefits in terms of
// wall and cpu time, and memory usage.
//
// Benchmarks (as of Dec 2018) show that codecgen gives about
//
//   - for binary formats (cbor, etc): 25% on encoding and 30% on decoding to/from []byte
//   - for text formats (json, etc): 15% on encoding and 25% on decoding to/from []byte
//
// Note that (as of Dec 2018) codecgen completely ignores
//
// - MissingFielder interface
//   (if you types implements it, codecgen ignores that)
// - decode option PreferArrayOverSlice
//   (we cannot dynamically create non-static arrays without reflection)
//
// In explicit package terms: codecgen generates codec.Selfer implementations for a set of types.
package main

import (
	"bufio"
	"bytes"
	"errors"
	"flag"
	"fmt"
	"go/ast"
	"go/parser"
	"go/token"
	"math/rand"
	"os"
	"os/exec"
	"path/filepath"
	"regexp"
	"strconv"
	"strings"
	"text/template"
	"time"
)

const genCodecPkg = "codec1978" // keep this in sync with codec.genCodecPkg

const genFrunMainTmpl = `//+build ignore
// Code generated - temporary main package for codecgen - DO NOT EDIT.
package main
{{ if .Types }}import "{{ .ImportPath }}"{{ end }}
func main() {
	{{ $.PackageName }}.CodecGenTempWrite{{ .RandString }}()
}
`

// const genFrunPkgTmpl = `//+build codecgen
const genFrunPkgTmpl = `
// Code generated - temporary package for codecgen - DO NOT EDIT.
package {{ $.PackageName }}
import (
	{{ if not .CodecPkgFiles }}{{ .CodecPkgName }} "{{ .CodecImportPath }}"{{ end }}
	"os"
	"reflect"
	"bytes"
	"strings"
	"go/format"
)
func CodecGenTempWrite{{ .RandString }}() {
	os.Remove("{{ .OutFile }}")
	fout, err := os.Create("{{ .OutFile }}")
	if err != nil {
		panic(err)
	}
	defer fout.Close()
	
	var typs []reflect.Type
	var typ reflect.Type
	var numfields int
{{ range $index, $element := .Types }}
	var t{{ $index }} {{ . }}
typ = reflect.TypeOf(t{{ $index }})
	typs = append(typs, typ)
	if typ.Kind() == reflect.Struct { numfields += typ.NumField() } else { numfields += 1 }
{{ end }}
	// println("initializing {{ .OutFile }}, buf size: {{ .AllFilesSize }}*16",
	// 	{{ .AllFilesSize }}*16, "num fields: ", numfields)
	var out = bytes.NewBuffer(make([]byte, 0, numfields*1024)) // {{ .AllFilesSize }}*16
	{{ if not .CodecPkgFiles }}{{ .CodecPkgName }}.{{ end }}Gen(out,
		"{{ .BuildTag }}", "{{ .PackageName }}", "{{ .RandString }}", {{ .NoExtensions }},
		{{ if not .CodecPkgFiles }}{{ .CodecPkgName }}.{{ end }}NewTypeInfos(strings.Split("{{ .StructTags }}", ",")),
		 typs...)
	bout, err := format.Source(out.Bytes())
	// println("... lengths: before formatting: ", len(out.Bytes()), ", after formatting", len(bout))
	if err != nil {
		fout.Write(out.Bytes())
		panic(err)
	}
	fout.Write(bout)
}
`

// Generate is given a list of *.go files to parse, and an output file (fout).
//
// It finds all types T in the files, and it creates 2 tmp files (frun).
//   - main package file passed to 'go run'
//   - package level file which calls *genRunner.Selfer to write Selfer impls for each T.
// We use a package level file so that it can reference unexported types in the package being worked on.
// Tool then executes: "go run __frun__" which creates fout.
// fout contains Codec(En|De)codeSelf implementations for every type T.
//
func Generate(outfile, buildTag, codecPkgPath string,
	uid int64,
	goRunTag string, st string,
	regexName, notRegexName *regexp.Regexp,
	deleteTempFile, noExtensions bool,
	infiles ...string) (err error) {
	// For each file, grab AST, find each type, and write a call to it.
	if len(infiles) == 0 {
		return
	}
	if codecPkgPath == "" {
		return errors.New("codec package path cannot be blank")
	}
	if outfile == "" {
		return errors.New("outfile cannot be blank")
	}
	if uid < 0 {
		uid = -uid
	} else if uid == 0 {
		rr := rand.New(rand.NewSource(time.Now().UnixNano()))
		uid = 101 + rr.Int63n(9777)
	}
	// We have to parse dir for package, before opening the temp file for writing (else ImportDir fails).
	// Also, ImportDir(...) must take an absolute path.
	lastdir := filepath.Dir(outfile)
	absdir, err := filepath.Abs(lastdir)
	if err != nil {
		return
	}
	importPath, err := pkgPath(absdir)
	if err != nil {
		return
	}
	type tmplT struct {
		CodecPkgName    string
		CodecImportPath string
		ImportPath      string
		OutFile         string
		PackageName     string
		RandString      string
		BuildTag        string
		StructTags      string
		Types           []string
		AllFilesSize    int64
		CodecPkgFiles   bool
		NoExtensions    bool
	}
	tv := tmplT{
		CodecPkgName:    genCodecPkg,
		OutFile:         outfile,
		CodecImportPath: codecPkgPath,
		BuildTag:        buildTag,
		RandString:      strconv.FormatInt(uid, 10),
		StructTags:      st,
		NoExtensions:    noExtensions,
	}
	tv.ImportPath = importPath
	if tv.ImportPath == tv.CodecImportPath {
		tv.CodecPkgFiles = true
		tv.CodecPkgName = "codec"
	} else {
		// HACK: always handle vendoring. It should be typically on in go 1.6, 1.7
		tv.ImportPath = stripVendor(tv.ImportPath)
	}
	astfiles := make([]*ast.File, len(infiles))
	var fi os.FileInfo
	for i, infile := range infiles {
		if filepath.Dir(infile) != lastdir {
			err = errors.New("all input files must all be in same directory as output file")
			return
		}
		if fi, err = os.Stat(infile); err != nil {
			return
		}
		tv.AllFilesSize += fi.Size()

		fset := token.NewFileSet()
		astfiles[i], err = parser.ParseFile(fset, infile, nil, 0)
		if err != nil {
			return
		}
		if i == 0 {
			tv.PackageName = astfiles[i].Name.Name
			if tv.PackageName == "main" {
				// codecgen cannot be run on types in the 'main' package.
				// A temporary 'main' package must be created, and should reference the fully built
				// package containing the types.
				// Also, the temporary main package will conflict with the main package which already has a main method.
				err = errors.New("codecgen cannot be run on types in the 'main' package")
				return
			}
		}
	}

	// keep track of types with selfer methods
	// selferMethods := []string{"CodecEncodeSelf", "CodecDecodeSelf"}
	selferEncTyps := make(map[string]bool)
	selferDecTyps := make(map[string]bool)
	for _, f := range astfiles {
		for _, d := range f.Decls {
			// if fd, ok := d.(*ast.FuncDecl); ok && fd.Recv != nil && fd.Recv.NumFields() == 1 {
			if fd, ok := d.(*ast.FuncDecl); ok && fd.Recv != nil && len(fd.Recv.List) == 1 {
				recvType := fd.Recv.List[0].Type
				if ptr, ok := recvType.(*ast.StarExpr); ok {
					recvType = ptr.X
				}
				if id, ok := recvType.(*ast.Ident); ok {
					switch fd.Name.Name {
					case "CodecEncodeSelf":
						selferEncTyps[id.Name] = true
					case "CodecDecodeSelf":
						selferDecTyps[id.Name] = true
					}
				}
			}
		}
	}

	// now find types
	for _, f := range astfiles {
		for _, d := range f.Decls {
			if gd, ok := d.(*ast.GenDecl); ok {
				for _, dd := range gd.Specs {
					if td, ok := dd.(*ast.TypeSpec); ok {
						// if len(td.Name.Name) == 0 || td.Name.Name[0] > 'Z' || td.Name.Name[0] < 'A' {
						if len(td.Name.Name) == 0 {
							continue
						}

						
						switch td.Type.(type) {
						case *ast.StructType, *ast.Ident, *ast.MapType, *ast.ArrayType, *ast.ChanType:
							// only add to tv.Types iff
							//   - it matches per the -r parameter
							//   - it doesn't match per the -nr parameter
							//   - it doesn't have any of the Selfer methods in the file
							if regexName.FindStringIndex(td.Name.Name) != nil &&
								notRegexName.FindStringIndex(td.Name.Name) == nil &&
								!selferEncTyps[td.Name.Name] &&
								!selferDecTyps[td.Name.Name] {
								tv.Types = append(tv.Types, td.Name.Name)
							}
						}
					}
				}
			}
		}
	}

	if len(tv.Types) == 0 {
		return
	}

	

	frunMainName := filepath.Join(lastdir, "codecgen-main-"+tv.RandString+".generated.go")
	frunPkgName := filepath.Join(lastdir, "codecgen-pkg-"+tv.RandString+".generated.go")
	if _, err = gen1(frunMainName, genFrunMainTmpl, &tv); err != nil {
		return
	}
	if _, err = gen1(frunPkgName, genFrunPkgTmpl, &tv); err != nil {
		return
	}

	// remove outfile, so "go run ..." will not think that types in outfile already exist.
	os.Remove(outfile)

	// execute go run frun
	cmd := exec.Command("go", "run", "-tags", "codecgen.exec safe "+goRunTag, frunMainName) //, frunPkg.Name())
	cmd.Dir = lastdir
	var buf bytes.Buffer
	cmd.Stdout = &buf
	cmd.Stderr = &buf
	if err = cmd.Run(); err != nil {
		err = fmt.Errorf("error running 'go run %s': %v, console: %s",
			frunMainName, err, buf.Bytes())
		return
	}
	os.Stdout.Write(buf.Bytes())


	if deleteTempFile {
		os.Remove(frunMainName)
		os.Remove(frunPkgName)
	}

	return
}

func gen1(frunName, tmplStr string, tv interface{}) (frun *os.File, err error) {
	os.Remove(frunName)
	if frun, err = os.Create(frunName); err != nil {
		return
	}
	defer frun.Close()

	t := template.New("")
	if t, err = t.Parse(tmplStr); err != nil {
		return
	}
	bw := bufio.NewWriter(frun)
	if err = t.Execute(bw, tv); err != nil {
		bw.Flush()
		return
	}
	if err = bw.Flush(); err != nil {
		return
	}
	return
}
func stripVendor(s string) string {
	// HACK: Misbehaviour occurs in go 1.5. May have to re-visit this later.
	// if s contains /vendor/ OR startsWith vendor/, then return everything after it.
	const vendorStart = "vendor/"
	const vendorInline = "/vendor/"
	if i := strings.LastIndex(s, vendorInline); i >= 0 {
		s = s[i+len(vendorInline):]
	} else if strings.HasPrefix(s, vendorStart) {
		s = s[len(vendorStart):]
	}
	return s
}

func main() {
	o := flag.String("o", "", "out file")
	c := flag.String("c", genCodecPath, "codec path")
	t := flag.String("t", "", "build tag to put in file")
	r := flag.String("r", ".*", "regex for type name to match")
	nr := flag.String("nr", "^$", "regex for type name to exclude")
	rt := flag.String("rt", "", "tags for go run")
	st := flag.String("st", "codec,json", "struct tag keys to introspect")
	x := flag.Bool("x", false, "keep temp file")
	_ = flag.Bool("u", false, "Allow unsafe use. ***IGNORED*** - kept for backwards compatibility: ")
	d := flag.Int64("d", 0, "random identifier for use in generated code")
	nx := flag.Bool("nx", false, "do not support extensions - support of extensions may cause extra allocation")

	flag.Parse()
	err := Generate(*o, *t, *c, *d, *rt, *st,
		regexp.MustCompile(*r), regexp.MustCompile(*nr), !*x, *nx, flag.Args()...)
	if err != nil {
		fmt.Fprintf(os.Stderr, "codecgen error: %v\n", err)
		os.Exit(1)
	}
}